Field of the Invention
The present invention relates to wireless communications, and more particularly, to a method and apparatus for performing a measurement in a wireless communication system.
Related Art
3rd generation partnership project (3GPP) long term evolution (LTE) evolved from a universal mobile telecommunications system (UMTS) is introduced as the 3GPP release 8. The 3GPP LTE uses orthogonal frequency division multiple access (OFDMA) in a downlink, and uses single carrier-frequency division multiple access (SC-FDMA) in an uplink. The 3GPP LTE employs multiple input multiple output (MIMO) having up to four antennas. In recent years, there is an ongoing discussion on 3GPP LTE-advanced (LTE-A) evolved from the 3GPP LTE.
A measurement is used for ensuring a mobility of a user equipment (UE) or is used for offloading. Quality of a neighboring cell is measured to move the UE to a corresponding cell if a better service than a current serving cell can be provided.
With the advancement of wireless communications, various types of cells are introduced to provide various types of services to a user. For example, a closed subscriber group (CSG) cell provides a high-quality quality of service (QoS) to a specific subscriber. A micro cell such as a pico cell, a femto cell, etc., is used to disperse many users concentrated in a small coverage.
There is provided a method of performing a measurement in an environment in which various cells are concentrated.